Researchers demonstrated that drug levels inside the body can be tracked in real time using a custom smartwatch that analyzes the chemicals found in sweat. This wearable technology could be incorporated into a more personalized approach to medicine in which an ideal drug and dosages can be tailored to an individual.

Current efforts to personalize drug dosage rely heavily on repeated blood draws. The samples are then sent out to be analyzed in central labs. These solutions are inconvenient, time-consuming, invasive, and expensive, which is why they are only performed on a small subset of patients and on rare occasions. The new wearable technology can track the profile of medication inside the body continuously and non-invasively, tailoring the optimal dosage and timing of the intake for each individual.

Because of their small molecular sizes, many different kinds of drugs end up in sweat, where their concentrations closely reflect the drugs’ circulating levels. That’s why the researchers created a smartwatch, equipped with a sensor that analyzes the sampled tiny droplets of sweat. The experiment tracked the effect of acetaminophen, a common over-the-counter pain medication, on individuals over the period of a few hours. First, the researchers stimulated sweat glands on the wrist by applying a small electric current. This allowed the researchers to detect changes in body chemistry without needing subjects to work up a sweat by exercising. As different drugs each have their own unique electrochemical signature, the sensor can be designed to look for the level of a particular medication at any given time.

The smartwatch is equipped with a sensor that analyzes the sampled tiny droplets of sweat. (Image credit: Jialun Zhu, Shuyu Lin, and Yichao Zhao, I²BL/UCLA)

Emerging pharmacogenomic solutions, which allow selection of drugs based on the genetic makeup of individuals, have shown to be useful in improving the efficacy of treatments. In combination with the wearable solution, which helps optimize the drug dosages for each individual, approaches to pharma-cotherapy can be personalized.

The technology accurately detects a drug’s unique electrochemical signal against the backdrop of signals from many other molecules that may be circulating in the body and in higher concentrations than the drug. The technology could be adapted to monitor medication adherence and drug abuse. It could be particularly important for individuals with mental health issues, for which doctors prescribe prolonged pharmacotherapy treatments.

For more information, contact Sam Emaminejad, Asst. Professor of Electrical and Computer Engineering, at This email address is being protected from spambots. You need JavaScript enabled to view it.; 310-206-2307.